The series features plenty of moving parts -- some less satisfying than others -- but far from lumbering like one of its zombies, "Dead" is now gliding along like a well-oiled machine.

In hindsight, “The Walking Dead’s” second season was a minor miracle, weathering the offscreen tumult of showrunner Frank Darabont’s abrupt departure, as well as the lofty expectations fostered by its instant-hit status. That the show delivered so ably under the stewardship of Glen Mazzara makes season three less surprising but no less riveting, with the first couple of episodes offering a buffet of character, tension and the inevitable can-you-top-this, stomach-churning gore. The series features plenty of moving parts — some less satisfying than others — but far from lumbering like one of its zombies, “Dead” is now gliding along like a well-oiled machine.

Last season’s finishing kick (and the only spoilers here will involve those events) underscored how no one is entirely safe in this post-apocalyptic world populated by ravenous zombies, while fundamentally altering the relationship between the ostensible hero, Rick (Andrew Lincoln), and his wife Lori (Sarah Wayne Callies). Her dalliance with her husband’s friend while thinking Rick dead finally came to a fatal conclusion, partly due to her manipulation of both men.

The third season finds at least one core character scattered, a brutal and more ruthless Rick leading the group, and a perfectly spooky new setting in an abandoned (or is it?) prison, which would seem to offer a safe haven — at least, once the minor complication involving its zombie population is addressed.

“Dead” has taken the intriguing step of using Robert Kirkman’s comics as merely a loose blueprint, allowing the TV show to follow its own path — and more significantly, not be constrained by a two-dimensional reality that doesn’t always translate directly to the screen.

Like “Breaking Bad,” the show also capitalizes on its exaggerated setting as a way to set up fascinating moral dilemmas, swallowing the brains of its fans in a way that’s less ostentatious than the show’s most overt threat. In that respect, the producers employ what amounts to a bit of marketing jujitsu — using zombies and gore to hook men on what is, at its foundation, (gasp) a soap opera.

The first two hours provide fleeting contact with one of the comicbook characters joining the series this season, the blade-wielding Michonne (Danai Gurira); another, the Governor (David Morrissey), is set to appear in later episodes. So for fans, there’s a whole lot of action still to come.

“It’s not time for a picnic,” Rick growls at one point, perfectly capturing one of the show’s central strengths — namely, there’s never a moment when the survivors, or the viewers, can fully let their guard down.

By contrast, AMC can rest easy. Because “Walking Dead” — having metamorphosed into its own cottage industry, including games and a companion talkshow — is clearly a series with a whole lot of life left in it.